This invention relates to a motorized device known by the designation motorized spindle. The invention also relates to a machine tool equipped with at least one aforementioned device.
The devices of the aforementioned type comprise:
a first element which is made up of a tubular wall having two opposite ends, and has a channel and a longitudinal axis extending substantially axially with respect to the device,
a second element which, connected to one of the ends of the first element, is made up of a spindle nose, i.e. an element of coupling with a piece of equipment such as a mandrel,
a third element which, disposed about the first element, is made up of a means of guiding this first element in rotation about its longitudinal axis, and this relative to a fourth element intended to achieve a connection between the device and a support,
a fifth element which, situated around the first element, is made up of a means for driving the said first element in rotation.
The rotational guiding means is of a type allowing a very precise guiding of the spindle in rotation, and this within a very wide range of rotational speeds.
The manufacture of various parts of this rotational guiding means requires possession of special know-how, in addition to adapted tools.
The means for driving in rotation used in this context is also of a special type, and besides adapted tools, the manufacture of the different parts of this means for driving in rotation likewise requires special know-how.
The known devices of the aforementioned type are costly to manufacture because they require their maker to have at one and the same time a mastery of the art of manufacture of different parts of the electric motor and the art of manufacture of different parts of the rotational guiding means.
One object of the invention is to achieve a device the manufacture of which is not subject to this constraint.
To this end, the invention has as its subject matter a device of the aforementioned type, wherein in particular:
the fifth element is itself constructed around an elongated piece perforated by an axial channel, which elongated piece is referred to as the sixth element,
the axial channel of the sixth element is of an inner diameter greater than the outer diameter of the first element such that the said sixth element is able to be engaged along its longitudinal axis on the first element,
at least one of the elements, which are the first element and the sixth element, is equipped with a seventh element, the function of which is to ensure the coupling in rotation of the said first and sixth elements.
The invention also has as its subject matter a machining center equipped with at least one aforementioned device.